This should be easy...Circuit Diagram help please.

[ReallyStuck]

Hi,

This is my first post, just looking for some assistance please with achieving the following:

I have 1 socket(I intend to attach a variety of devices to, the details are not important) and 6 cells that I intend to have connected to the socket via a switch which will enable me to select a given combination of those cells.
The cells.
2xCR123 (3V battery)
4xAA(1.5V battery)
The layout will be such that there will only ever be 1 type of battery connected, and they will be placed in pairs(2 cells in series). e.g. I will have either just the one pair of CR123 batteries, or two pairs of the AA batteries at any given time. (I say this as the circuit will be similar to that of a torch that can accommodate multiple battery types).

I've attached a diagram of the components.

My intended combinations(or rather options that are to be selected by the switch) are as follows:
1 - OFF
2 - 2xCR123(series) = 2x3V = 6V
3 - 4xAA(series) = 4x1.5V = 6V
4 - 4xAA(parallel) = 4x1.5V/2 = 3V
5 - 2xAA(series)[1st pair] = 2x1.5V = 3V
6 - 2xAA(series)[2nd pair] = 2x1.5V = 3V

So any help with coming up with a nice and concise circuit diagram would be greatly appreciated. (I've no idea what type of "switch" is required either.)
cheers.

 

[alec_t]

I intend to attach a variety of devices to, the details are not important

The maximum current taken by the intended loads is important in deciding on the best type of switch(es) to be used.
One possible problem with using the same AA cells both in parallel and in series is that some may get discharged before others. If the discharged cells are then used in series with 'good' cells the discharged ones may become reverse polarised, or their internal resistance may limit current too much.

 

[JimB]

If I understand correctly, you have several items (devices) which you wish to connect to a battery pack.

There will only ever be one device connected to the battery pack at a time.

Each device requires a different configuration of batteries.

You want a switch in the battery pack to select the various configurations as you have listed in your original post.



I would suggest that such a switch would be very complicated and expensive and may not be necessary.
The connector which you will use to connect the devices to the battery pack, why not make it a multi-pin connector?
When the device is connected to the battery pack, the plug on the device is wired so that it connects to the batteries which the device requires.
Have a look at the attachment, a crude sketch, but I hope you get the idea.

A final thought, why on earth do you need all these different batteries, there must be a simpler way?

JimB

 

[alec_t]

JimB's suggestion to use a multi-pin connector would prevent the disaster of connecting a 6V supply to a 3V device.

 

[KJ6EAD]

Echoing Alec_t's sentiments:

...the details are not important...

Can you at least give us an idea how much current would be drawn in each instance from these mystery loads?